Technical Field
The present invention relates to an ink, recorded matter, an ink container, a recording device, and a recording method.
Description of the Related Art
Inkjet recording methods have advantages such that the process is simple and full colorization is easy in comparison with other recording methods. Therefore, high resolution images can be obtained by a device having a simple configuration. For this reason, the inkjet recording is widely diffusing from home use to office use, commercial printing, and industrial printing. In such an inkjet recording method, an aqueous ink composition using a water soluble dye as a coloring material are commonly used. However, its water resistance and light resistance are inferior so that pigment ink using a water insoluble pigment is under development to substitute the water soluble dye.
For inkjet ink printing for office use, recording media, typically plain paper, are used and high image density is demanded. In general, when images are printed on plain paper using pigment ink, the pigment ink does not stay on the surface of the paper but permeates into the paper, so that the density of the pigment on the surface decreases and consequently the image density lowers. The image density increases if the pigment concentration in the ink is increased. However, the ink becomes viscous, thereby degrading the discharging stability of the ink.
In attempts to improve the print performance, a measure for quick drying in which a permeating agent such as a hydrophobic solvent, etc., is added to an ink to permeate water into a recording medium has been taken to speed up drying of the ink attached to a recording medium. For this reason, dispersion stability in an environment including both a pigment dispersion of a water solvent and an ink of a hydrophobic solvent is required.
In addition, unlike an aqueous dye ink prepared by dissolving a dye in water, the aqueous pigment ink for use in the inkjet recording method described above or pens and pencils requires stable dispersion of an water-insoluble pigment in water for a long period of time. Therefore, various pigment dispersants have been developed.